Zinc Oxide Eugenol (or) ZOE is a Irreversible Rigid Impression material used as a secondary technique to take impression of Edentulous patients with the help of Mucocompessive technique.
As seen in the name this impression material is made up of Zinc Oxide and Eugenol (Oil of cloves).
Classification:
It is classified by ADA with the ADA Specification N.o: 16
- Type I: Hard
- Type II: Soft
Composition:
This Impression material is available in paste form in 2 tubes:
- Base Paste (White)
- Accelerator Paste/ Reactor/ Catalayst Paste (Red)
Base Paste:
- Zinc Oxide – 87%
- Olive Oil – 13%
Accelerator Paste:
- Oil of Cloves – 12%
- Gum or Polymerized Rosin – 50%
- Filler(Silica type) – 20%
- Lanolin – 3%
- Resinious Balasam – 10%
- Accelerator Solution – 5%
Setting Reaction :
ZnO + H2O ? Zn (OH)2
Zn (OH)2 + 2HE ? ZnE2+ 2 H2O
Manipulation:
- Dispense equal length of the 2 pastes. Variation in length alters setting time.
- Paper pad is used as a mixing slab & a stiff stainless steel spatula with an 8-10 cm blade should be used.
- Mixing is done for 30-40 sec until no color streaks in the mix are seen & a uniform consistency is obtained.
- The mix is then transferred to a impression tray to take an impression.
Factors controlling setting time:
Decreasing setting time:
· Small amt. of zinc acetate
· Accelerators
· Small drop of water mixed in the paste containing eugenol
· Increasing the mixing time.
· Increasing accelerator paste while mixing.
Increasing setting time:
· Cooling the spatula & mixing slab
· Addition of inert oils & waxes during mixing to reduce hardness like: olive oil.
· Increasing base paste while mixing.
Properties:
i) consistency & flow
-thick consistency compress the tissues.
ii) dimensional stability
-quite satisfactory,
-less than 0.1 % shrinkage occurs during hardening.
iii) reproduction of details
-good.
Biologic considerations:
Some patients experience burning sensation in the mouth due to eugenol & can also cause tissue irritation. This maybe overcome by using a non eugenol paste.
Uses:
1. cementing & insulating medium
2. temporary filling
3. root canal filling material
4. surgical pack in periodontal surgical procedures.
5. bite registration pastes
6. temporary relining material for dentures.
7. impression material for edentulous patients.
Advantages:
1. Good dimensional stability
2. good detail reproduction
3. impression surface can be modified by adding in deficient areas
4. easy to manipulate
5. long working time, so border moulding can be done while relining dentures.
Disadvantages:
1. burning sensation due to eugenol.
2. messy to work with
3. sticks to skin & instruments , difficult to clean.
4. rigid so tends to break off in areas of undercuts.
VERY GOOD
Thank you sir for providing us with this helpful topic. Plz also help us in future. We all students of Govt Dental College Srinagar India need ur help to prove our best in the field of Dental Sciences. Thank Yoy once again. God bless you.
Really helpful material….thanks a ton….
iam realy thankful…sir…..to provide the matter..which is very much helpfull 2 me….!!thanks a lot…..!!
Hi,
do you have a video for impression paste (ZOE) preparation , could you answer me as soon as you can …please i need it
Thanks
Thanks a Lot that was very Helpful :)
good work
its useful.thanks
love it
How long can we delay the pouring of cast in zoe impression
Thanks and Thanks
really really helpful …thanks a lot
Its really helpful for dental students.
It is really helpful. Could you please include the roles of the components of the accelerator paste. thanks a lot
What is used instead of eugenol in non eugenol pastes????
Tnku Boss for proving information about this topic..
Good
What is the purpose of using vasline along with ZOE manipulation
Please where I get this product
Need it urgently
For how long can we store Zinc oxide eugenol impression and under what conditions?
According to certain studies in ncbi.nlm..nih.gov (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376546/) it is given that the ideal time for storing or pouring an Impression is anywhere between 0 to 7 hours.